Proyectos de Subversion Moodle

<?php

// This file is part of Moodle - http://moodle.org/

//

// Moodle is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

//

// Moodle is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

//

// You should have received a copy of the GNU General Public License

// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**

 * Base for all file browsing classes.

 *

 * @package    core_files

 * @copyright  2008 Petr Skoda (http://skodak.org)

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

defined('MOODLE_INTERNAL') || die();

/**

 * Base class for things in the tree navigated by {@link file_browser}.

 *

 * @package    core_files

 * @copyright  2008 Petr Skoda (http://skodak.org)

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

abstract class file_info {

    /** @var context File context */

    protected $context;

    /** @var file_browser File browser instance */

    protected $browser;

    /**

     * Constructor

     *

     * @param file_browser $browser file_browser instance

     * @param stdClass $context

     */

    public function __construct($browser, $context) {

        $this->browser = $browser;

        $this->context = $context;

    }

    /**

     * Returns list of standard virtual file/directory identification.

     * The difference from stored_file parameters is that null values

     * are allowed in all fields

     *

     * @return array with keys contextid, component, filearea, itemid, filepath and filename

     */

    public function get_params() {

        return array('contextid' => $this->context->id,

                     'component' => null,

                     'filearea'  => null,

                     'itemid'    => null,

                     'filepath'  => null,

                     'filename'  => null);

    }

    /**

     * Returns localised visible name.

     *

     * @return string

     */

    abstract public function get_visible_name();

    /**

     * Whether or not this is a directory

     *

     * @return bool

     */

    abstract public function is_directory();

    /**

     * Returns list of children.

     *

     * @return array of file_info instances

     */

    abstract public function get_children();

    /**

     * Builds SQL sub query (WHERE clause) for selecting files with the specified extensions

     *

     * If $extensions == '*' (any file), the result is array('', array())

     * otherwise the result is something like array('AND filename ...', array(...))

     *

     * @param string|array $extensions - either '*' or array of lowercase extensions, i.e. array('.gif','.jpg')

     * @param string $prefix prefix for DB table files in the query (empty by default)

     * @return array of two elements: $sql - sql where clause and $params - array of parameters

     */

    protected function build_search_files_sql($extensions, $prefix = null) {

        global $DB;

        if ($prefix && strlen($prefix)) {

            $prefix = $prefix . '.';

        } else {

            $prefix = '';

        }

        $sql = '';

        $params = array();

        if (is_array($extensions) && !in_array('*', $extensions)) {

            $likes = array();

            $cnt = 0;

            foreach ($extensions as $ext) {

                $cnt++;

                $likes[] = $DB->sql_like($prefix.'filename', ':filename'.$cnt, false);

                $params['filename'.$cnt] = '%'.$ext;

            }

            $sql .= ' AND (' . join(' OR ', $likes) . ')';

        }

        return array($sql, $params);

     }

    /**

     * Returns list of children which are either files matching the specified extensions

     * or folders that contain at least one such file.

     *

     * It is recommended to overwrite this function so it uses a proper SQL

     * query and does not create unnecessary file_info objects (might require a lot of time

     * and memory usage on big sites).

     *

     * @param string|array $extensions, either '*' or array of lowercase extensions, i.e. array('.gif','.jpg')

     * @return array of file_info instances

     */

    public function get_non_empty_children($extensions = '*') {

        $list = $this->get_children();

        $nonemptylist = array();

        foreach ($list as $fileinfo) {

            if ($fileinfo->is_directory()) {

                if ($fileinfo->count_non_empty_children($extensions)) {

                    $nonemptylist[] = $fileinfo;

                }

            } else if ($extensions === '*') {

                $nonemptylist[] = $fileinfo;

            } else {

                $filename = $fileinfo->get_visible_name();

                $extension = core_text::strtolower(pathinfo($filename, PATHINFO_EXTENSION));

                if (!empty($extension) && in_array('.' . $extension, $extensions)) {

                    $nonemptylist[] = $fileinfo;

                }

            }

        }

        return $nonemptylist;

    }

    /**

     * Returns the number of children which are either files matching the specified extensions

     * or folders containing at least one such file.

     *

     * We usually don't need the exact number of non empty children if it is >=2 (see param $limit)

     * This function is used by repository_local to evaluate if the folder is empty. But

     * it also can be used to check if folder has only one subfolder because in some cases

     * this subfolder can be skipped.

     *

     * It is strongly recommended to overwrite this function so it uses a proper SQL

     * query and does not create file_info objects (later might require a lot of time

     * and memory usage on big sites).

     *

     * @param string|array $extensions, for example '*' or array('.gif','.jpg')

     * @param int $limit stop counting after at least $limit non-empty children are found

     * @return int

     */

    public function count_non_empty_children($extensions = '*', $limit = 1) {

        $list = $this->get_children();

        $cnt = 0;

        // first loop through files

        foreach ($list as $fileinfo) {

            if (!$fileinfo->is_directory()) {

                if ($extensions !== '*') {

                    $filename = $fileinfo->get_visible_name();

                    $extension = core_text::strtolower(pathinfo($filename, PATHINFO_EXTENSION));

                    if (empty($extension) || !in_array('.' . $extension, $extensions)) {

                        continue;

                    }

                }

                if ((++$cnt) >= $limit) {

                    return $cnt;

                }

            }

        }

        // now loop through directories

        foreach ($list as $fileinfo) {

            if ($fileinfo->is_directory() && $fileinfo->count_non_empty_children($extensions)) {

                if ((++$cnt) >= $limit) {

                    return $cnt;

                }

            }

        }

        return $cnt;

    }

    /**

     * Returns parent file_info instance

     *

     * @return file_info or null for root

     */

    abstract public function get_parent();

    /**

     * Returns array of url encoded params.

     *

     * @return array with numeric keys

     */

    public function get_params_rawencoded() {

        $params = $this->get_params();

        $encoded = array();

        $encoded[] = 'contextid=' . $params['contextid'];

        $encoded[] = 'component=' . $params['component'];

        $encoded[] = 'filearea=' . $params['filearea'];

        $encoded[] = 'itemid=' . (is_null($params['itemid']) ? -1 : $params['itemid']);

        $encoded[] = 'filepath=' . (is_null($params['filepath']) ? '' : rawurlencode($params['filepath']));

        $encoded[] = 'filename=' . ((is_null($params['filename']) or $params['filename'] === '.') ? '' : rawurlencode($params['filename']));

        return $encoded;

    }

    /**

     * Returns file download url

     *

     * @param bool $forcedownload whether or not force download

     * @param bool $https whether or not force https

     * @return string url

     */

    public function get_url($forcedownload=false, $https=false) {

        return null;

    }

    /**

     * Whether or not I can read content of this file or enter directory

     *

     * @return bool

     */

    public function is_readable() {

        return true;

    }

    /**

     * Whether or not new files or directories can be added

     *

     * @return bool

     */

    public function is_writable() {

        return true;

    }

    /**

     * Is this info area and is it "empty"? Are there any files in subfolders?

     *

     * This is used mostly in repositories to reduce the

     * number of empty folders. This method may be very slow,

     * use with care.

     *

     * @return bool

     */

    public function is_empty_area() {

        return false;

    }

    /**

     * Returns file size in bytes, null for directories

     *

     * @return int bytes or null if not known

     */

    public function get_filesize() {

        return null;

    }

    /**

     * Returns mimetype

     *

     * @return string mimetype or null if not known

     */

    public function get_mimetype() {

        return null;

    }

    /**

     * Returns time created unix timestamp if known

     *

     * @return int timestamp or null

     */

    public function get_timecreated() {

        return null;

    }

    /**

     * Returns time modified unix timestamp if known

     *

     * @return int timestamp or null

     */

    public function get_timemodified() {

        return null;

    }

    /**

     * Returns the license type of the file

     * @return string license short name or null

     */

    public function get_license() {

        return null;

    }

    /**

     * Returns the author name of the file

     *

     * @return string author name or null

     */

    public function get_author() {

        return null;

    }

    /**

     * Returns the source of the file

     *

     * @return string a source url or null

     */

    public function get_source() {

        return null;

    }

    /**

     * Returns the sort order of the file

     *

     * @return int

     */

    public function get_sortorder() {

        return 0;

    }

    /**

     * Whether or not this is a external resource

     *

     * @return bool

     */

    public function is_external_file() {

        return false;

    }

    /**

     * Returns file status flag.

     *

     * @return int 0 means file OK, anything else is a problem and file can not be used

     */

    public function get_status() {

        return 0;

    }

    /**

     * Returns the localised human-readable name of the file together with virtual path

     *

     * @see file_info_stored::get_readable_fullname()

     * @return string

     */

    public function get_readable_fullname() {

        return null;

    }

    /**

     * Create new directory, may throw exception - make sure

     * params are valid.

     *

     * @param string $newdirname name of new directory

     * @param int $userid id of author, default $USER->id

     * @return file_info new directory

     */

    public function create_directory($newdirname, $userid = NULL) {

        return null;

    }

    /**

     * Create new file from string - make sure

     * params are valid.

     *

     * @param string $newfilename name of new file

     * @param string $content of file

     * @param int $userid id of author, default $USER->id

     * @return file_info new file

     */

    public function create_file_from_string($newfilename, $content, $userid = NULL) {

        return null;

    }

    /**

     * Create new file from pathname - make sure

     * params are valid.

     *

     * @param string $newfilename name of new file

     * @param string $pathname location of file

     * @param int $userid id of author, default $USER->id

     * @return file_info new file

     */

    public function create_file_from_pathname($newfilename, $pathname, $userid = NULL) {

        return null;

    }

    /**

     * Create new file from stored file - make sure

     * params are valid.

     *

     * @param string $newfilename name of new file

     * @param int|stored_file $fid id or stored_file of file

     * @param int $userid id of author, default $USER->id

     * @return file_info new file

     */

    public function create_file_from_storedfile($newfilename, $fid, $userid = NULL) {

        return null;

    }

    /**

     * Delete file, make sure file is deletable first.

     *

     * @return bool success

     */

    public function delete() {

        return false;

    }

    /**

     * Copy content of this file to local storage, overriding current file if needed.

     *

     * @param array|stdClass $filerecord contains contextid, component, filearea,

     *    itemid, filepath, filename and optionally other attributes of the new file

     * @return bool success

     */

    public function copy_to_storage($filerecord) {

        return false;

    }

    /**

     * Copy content of this file to local storage, overriding current file if needed.

     *

     * @todo MDL-31068 implement move() rename() unzip() zip()

     * @param string $pathname real local full file name

     * @return boolean success

     */

    public function copy_to_pathname($pathname) {

        return false;

    }

//TODO: following methods are not implemented yet ;-)

    //public abstract function move(location params);

    //public abstract function rename(new name);

    //public abstract function unzip(location params);

    //public abstract function zip(zip file, file info);

}